Helicopters from Rickenbacker use 36.700/142.600/228.800 (alternate FM 34.700) for flight ops. Nothing is based at OSU, but they do stop by occasionally. I have also heard reports of 239.000 (AM and FM modes) from a unit member, but never confirmed it from listening.
The unit-to-unit comms might be ISR radios. Check those freqs and possibly even the 380-384 range for low power mobiles.
Jared Soergel (Twitter: @jsoergel949
Radios: BCD396XT, IC-R20 (x2), BC355N, PRO-76
Spotting gear: Canon EOS Rebel XS and EOS Rebel T2i, 18-55mm and 75-300mm lenses